I am looking at buying an 83 98 Brougham. The car is said to have 62k original miles. Hasn't been driven a lot in the last several years. I drove it today and the car ran out well but I did notice that the oil pressure gauge dropped completely off at stop lights. I didn't hear any engine noise.

Does this seem like a sending unit or maybe old oil problem from sitting? The oil was clear and clean with no gasoline smell when I checked it after the test drive. They had the car idling when I arrived because of a weak battery.

Is there any other points to inspect specific to these cars before making an offer? I am willing/able to do some tinkering, but really just looking for a big car I can enjoy